I just moved up to Seattle from LA & haven't had a chance to brew at the new house yet, so I'm not positive on the temp (but probably in the 50's, if not lower) or flowrate (hose bib in back is SLOW, but was thinking of getting a pump as well). In terms of pitching temp, I normally like to get down to the mid to low 60's. I'm doing 5-10 gallon batches, but after I get the Brewmagic system, I'll be going up to 15, max. Obviously I'd like to purchase a chiller now that will work for the future system.
I'll definitely check out the DudaDiesel website, but any specific recommendations? Thanks for the help!
So for my calculations, I am assuming your water temp to be 52f, as that is what google tells me it should be for Seattle. This will certainly change depending on the season (though you being on the coast it shouldn't fluctuate too much).
You mentioned low to mid 60's as your pitching, so I am just using 62f for all of these numbers, to keep it simple.
You mentioned slow water, so I am guessing 2-5 gpm. Ill run a set of best case numbers at 5 gpm, and then some worst case numbers at 2gpm.
With 5gpm water:
36a-20, $145 - 4 min 21 s to chill 10 gallons, using 22gal of water
23a-20, $99 - 6 min 15 s to chill 10 gallons, using 31.25 gal of water
12a-20, $60 - 12 min 30 s to chill 10 gallons, using 62.5 gal of water
With 2gpm water:
36a-20, $145 - 8 min even to chill 10 gallons, using 16 gal of water
23a-20, $99 - 10 min 38 s to chill 10 gallons, using 21.25 gal of water
12a-20, $60 - 18 min 52 s to chill 10 gallons, using 38 gal of water
These numbers are linear with batch size - that is, if it takes 8 min exact for 10 gallons, it will take 4 min for 5 gallons, 12 min for 15.
So really it all comes down to what your water flow actually is, and how much you want to spend up front vs time cost vs water cost. The one thing I can say for sure is do not get anything with more plates than 20. With your low water flow, you'll run into pooling issues that will cost efficiency.